A cross-country storm will explode in strength as it moves over the central United States Friday, delivering extreme weather to millions through the weekend, including the chance of multiple strong tornadoes.

Dangerous weather conditions will peak Saturday, with one of the most prolific tornado-producing setups in years expected to develop over the Deep South — with disastrous results likely.

Severe weather season usually begins to ramp up in March and lasts through the start of summer. The dramatic increase in sun angle during the month can spark wide variations in our large-scale weather patterns as pockets of cold, dry air descend south from Canada while warm, moist air surges north from the Gulf.